On Sun, Mar 29, 2009 at 12:24 PM, Ignacio Enriquez <nach...@gmail.com> wrote: > Hi everyone. > I still have some doubts of should I release or not? and the most > important reaons why should I or why shouldn't I do it. Any answer > would be very appreciated. > > Consider this: > > NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults]; > NSArray *rawArray = [defaults objectForKey:@"lastArray"]; > NSMutableArray *tempArray = [[NSMutableArray alloc] init]; > for(int i= 0; i< [rawArray count]; i++){ > NSDictionary *dic = [rawArray objectAtIndex:i]; > Mail *mail = [[Mail alloc] initWithDictionary:dic]; > [tempArray addObject:mail]; > [mail release]; > } > theArray = tempArray; > > Here theArray is a property: > > @property (nonatomic, retain) NSArray *theArray;
>From Cocoa's memory management rules <http://developer.apple.com/documentation/Cocoa/Conceptual/MemoryMgmt/Articles/mmObjectOwnership.html>: - You own any object you create. You "create" an object using a method whose name begins with “alloc” or “new” or contains “copy” (for example, alloc, newObject, or mutableCopy). - If you own an object, you are responsible for relinquishing ownership when you have finished with it. One way to relinquish ownership of an object is to send it a release message. In Cocoa terminology, relinquishing ownership of an object is typically referred to as "releasing" an object. - If you do not own an object, you must not release it. > So my doubts are: > Since is initialized by a class method , "defaults" must not be > released -> correct? Correct. You didn't create it or retain it, you don't release it > rawArray should be released? ([rawArray release] ?) I think the answer > is no but why? Correct. You didn't create it or retain it, you don't release it > dic should be released? ([dic release]?) I don't know... You didn't create it or retain it, you don't release it > tempArray should be released? I think the answer is: it depends. > Since theArray is retain I could do > > self.theArray = tempArray; > [tempArray release]; > > or > > theArray = tempArray; > > so, what is the difference between using self and assigning tempArray > to theArray directly? Assigning directly to the instance variable is just that; an assignment. No retain happens, no release happens, no method is called. Assigning through the property (i.e. self.theArray =) calls a method. That method will release the old value of theArray and retain the new value. > (specifically in this case what is the > difference (in terms of retain count)?) > And what would happen with the retaincount of another object that was > theArray before tempArray assignation? (in case of doing theArray = > tempArray) In this case, not using the property will cause whatever theArray *used* to point to to be leaked. -- Clark S. Cox III clarkc...@gmail.com _______________________________________________ Cocoa-dev mailing list (Cocoa-dev@lists.apple.com) Please do not post admin requests or moderator comments to the list. Contact the moderators at cocoa-dev-admins(at)lists.apple.com Help/Unsubscribe/Update your Subscription: http://lists.apple.com/mailman/options/cocoa-dev/archive%40mail-archive.com This email sent to arch...@mail-archive.com